An NIDDK K24 award is requested to provide support for Patrick J. Lustman, Ph.D., to enhance a program of research and mentoring in Comorbid Diabetes and Depression. Diabetes affects 16 million Americans. Another 21 million have impaired glucose tolerance and are at risk for developing type 2 diabetes (T2DM). Major depression more than doubles the risk of T2DM even after controlling for other risk factors. Major depression is also present in 20% of patients with existing diabetes (type 1 or type 2), is associated with hyperglycemia, and conveys a significantly increased risk for each of the major complications of the metabolic disorder. The overall goals of the applicant's research are: 1) to elucidate the mechanisms by which depression affects the risk course, and outcome of diabetes; and 2) to determine whether and how depression treatment may improve glycemic control and the long-term course of diabetes. The proposal describes the applicant's current research, some ideas for future studies, and the career development and mentoring activities that are planned over the 5-year interval of the K24. Two NIH (NIDDK)-supported trials are ongoing. One is to determine if maintenance antidepressant treatment in diabetes will prevent or delay depression recurrence and produce durable improvements in glycemic control. The second is to establish if treatment of prepartum depression in diabetes will improve glycemic control and thereby decrease maternal and neonatal morbidity. Trainees will engage in these projects, take didactic coursework in clinical investigation, and complete a research proposal over the two-year training interval. A series of career development activities (for the PI) are also described that include additional training in structural equation modeling using SAS, and training in performing and interpreting intravenous glucose tolerance tests using minimal model analysis. K24 support will provide the applicant with the protected time needed to determine the utility of depression treatment in the everyday management of those living with diabetes and, in the process, to increase the mentoring of beginning clinical investigators in behavioral diabetes.